NEW YORK — Sometime in 2010, the Transportation Security Administration (TSA) will stop swiping airline passengers’ bottled water and cups of coffee at security checkpoints. Instead, the agency will once again permit us to carry liquids and gels aboard planes.

It’s not that the TSA has finally realized mouthwash and moisturizer really can’t explode, not even at 30,000 feet. Rather, it claims it has a combination of new contraptions to prove that. Advanced Technology X-ray machines, bottle scanners, and spectrometers will confirm that your unopened, factory-sealed Listerine is, well, Listerine.

The ban on liquids and gels has plagued passengers for over two years now, ever since British police insisted they had foiled a plot for bombing jetliners en route from London to the US and Canada. Supposedly, terrorists planned to smuggle the ingredients of an explosive elixir aboard their flights in soft-drink containers, then combine them to blow the planes sky-high.

Horrific, murderous – and virtually impossible. The TSA makes it sound as though anyone with a year of high-school chemistry and some hydrogen peroxide can whip up explosives in an airplane’s restroom. But mixing a truly explosive bomb is a delicate operation. It requires exact temperatures, precise measurements and methods, and specialized equipment – all more commonly found in laboratories than lavatories. The procedure takes a while, too. And the fumes are likely to alert the passengers shifting from foot to foot in the aisle as they await their turn in the washroom.

In fact, chemists worldwide doubt that even the most accomplished terrorist can concoct such a combustive cocktail high above the Atlantic. A British jury this summer didn’t buy the allegations, either. Due to lack of evidence, only eight of the plot’s original 25 suspects finally made it to trial. As it turns out, police should have freed all the defendants: jurors refused to convict anyone of terrorism. They exonerated one man, returned no verdict on four others, and settled on lesser charges for the remaining three.

But none of these facts seem to matter to the TSA. It needs something to justify its existence: Despite six years of patting down passengers, it hasn’t reported uncovering a single terrorist. No wonder it latched onto the nonsense about liquid bombs. Ferreting out and confiscating everyday substances not only makes work for 43,000 screeners, it also fools us into thinking this protects us.

The TSA has always been a political, not practical, response to 9/11. It hassles us at checkpoints not because of penetrating insights on security or some brilliant breakthrough, but because politicians handed it power. Specialists in security didn’t invent the TSA; the Bush administration imposed it on us. So we might hope the incoming president would abolish this absurd agency.

Unfortunately, Barack Obama wants to improve the TSA rather than send it packing. His suggestions for that improvement? Passengers still aren’t screened against a comprehensive terrorist watch list, his website proclaims. Such a list must be developed.

Why? The watch list has already kept Rep. John Lewis (D) of Georgia and Sen. Ted Kennedy (D) of Massachusetts off planes: Will a comprehensive list bar Republican congressmen, too? That’ll protect us about as well as unionizing screeners will – another change the campaigning Obama said he favors.

An administration serious about preserving passengers’ lives rather than screeners’ jobs would dismantle the TSA. Experts in the field, not the government, should design security. And it’s senseless to fear that without the TSA airlines won’t protect us. Businesses never willingly risk their inventory or customers; the aviation industry is no exception.

Eliminating the TSA allows airlines to protect their customers and multimillion-dollar jets with real security, tailored to each company’s needs. AirTran, for instance, confronts different challenges from Air Jamaica, just as banks in midtown Manhattan deal with different dangers than do those in suburban Sioux City. In a world free of the TSA, an airline might arm its pilots or hire private security firms.

More likely, ideas and options we non-experts can’t imagine would render aviation’s security as unobtrusive and effective as it is in other industries. There’s no limit to human ingenuity and innovation – until the government stifles them with one-size-fits-all regulation.

Unfortunately, we can expect the airlines to fight as hard as the TSA for its survival: requiring security and establishing a bureaucracy to run it sticks taxpayers, rather than airlines, with the bill.

We’ve paid aviation’s operating costs long enough. It’s time to bring down the curtain on the TSA’s security theater.

Becky Akers, a freelance writer and historian, is finishing a book about the TSA.